Rewrite "make locale-gnu-*" in Python, so Win32 can use it too

Details

Description

Greg Stein pointed out that gen_make.py has all logic and information (when run
from autogen.sh) to eliminate the 'find' command in the Makefile. Also,
translators need to run the entire configure script, where it would be nice if
./autogen.sh would be enough.
Also, for our Win32 friends no framework is in place at all yet.